Brushed surface will get shinier the more you wear it. And shiny surface will get slightly mat.
Brass and silver jewelry might change to a darker tone when wearing it. It differ a lot from whom wears it and if you use perfume, lotion etc.
To minimize change in color do not shower or sleep in your jewelry and keep it in a dry. Do not leave your jewelry next to other metals. You can use clear nail polish on brass to avoid oxidation (works good with bolts)
To clean your jewelry there are silver and brass polish cloth or rinse. Microfiber cloth works well.